How Different Modes of Child Delivery Influence Abdominal Muscle Activities in the Active Straight Leg Raise

[Purpose] The purpose of this study was to examine the activities of the abdominalmuscles of women who had experienced vaginal delivery in comparison with those who hadexperienced Cesarean childbirth. [Subjects and Methods] A total of 14 subjects (7 vaginaldelivery, 7 Cesarean section) performed an active straight leg raise to 20 cm above theground, and we measured the activities of the internal oblique abdominal muscle, theexternal oblique abdominal muscle, and the rectus abdominal muscle on both sides usingelectromyography. The effort required to raise the leg was scored on a Likert scale. Then,the subjects conducted maximum isometric contraction for hip joint flexion with the legraised at 20 cm, and maximum torque and abdominal muscle activities were measured usingelectromyography. [Results] During the active straight leg raise, abdominal muscleactivities were higher in the Cesarean section subjects. The Likert scale did not show asignificant difference. The activities of the abdominal muscles and the maximum torque ofthe hip joint flexion at maximum isometric contraction were higher in the vaginal deliverysubjects. [Conclusion] The abdominal muscles of Cesarean section subjects showed greaterrecruitment for maintaining pelvic stability during the active straight leg raising, butwere relatively weaker when powerful force was required. Therefore, we consider that moreabdominal muscle training is necessary for maintaining pelvic stability of Cesareansection subjects.Key words: Modes of delivery, Abdominal muscle, Active straight leg raising